News
20-September 2010 – Latest
poultry research – LGC establishes new limits to protect
consumers
LGC study concludes that HADH method detects previously frozen
poultry
A research study by LGC has
confirmed that the current method used to protect consumers from
the fraudulent sale of previously frozen poultry as fresh is
accurate. The method can distinguish between poultry that has been
frozen then thawed and fresh or chilled poultry. However the
research also concluded that the method is unable to distinguish
between poultry that has been chilled conventionally and poultry
chilled by a new superchilling process.
European Commission (EC)
Regulations require whole poultry or parts be marketed as either
‘fresh’ or ‘chilled’ if they have been stored between -2°C and
+4°C. While whole poultry or parts can also be marketed as ‘frozen’
or ‘quick-frozen’, they are not permitted to be marketed as ‘fresh’
if they have been previously frozen and then thawed.
A new superchilling
refrigeration technology has been developed which can store poultry
meat in a partially frozen state between -3°C to -5°C for long
periods. Because this new refrigeration technology does not comply
with the EC Regulations, manufacturers may be mislabelling their
poultry meat.
LGC, an international
science-based company and market leader in analytical, forensic and
diagnostic services and reference standards, undertook the study,
which was funded by the Food Standards Agency, to assess the
extent to which the accepted ß-hydroxyacyl-CoA-dehydrogenase (HADH)
method can distinguish between poultry that has been conventionally
chilled or frozen and poultry chilled and frozen using new
refrigeration technologies.
The HADH method was
developed in earlier research and applied to the UK market. The
method is based on measuring the activity of a muscle mitochondrial
enzyme, ß-hydroxyacyl-CoA-dehydrogenase, which is released when the
mitochondrial membranes are damaged during freezing and thawing.
Measurement of the relative HADH activity in juice expressed from a
meat sample before and after a laboratory freezing process, gives
an indication as to whether or not the meat has been previously
frozen.
Results from LGC’s study
showed that the HADH assay was able to distinguish between poultry
that had been frozen, either conventionally or using a new
rapid-freezing technique and fresh or chilled poultry, but it was
unable to distinguish between normally chilled poultry and the new
superchilling process. Further detailed information on LGC’s study
results can be freely viewed within the Journal of the
Association of Public Analysts.
In the conclusion to its
study, LGC refined a new numerical cut-off limit for chicken and
improved the procedure used to extract cellular liquid from the
meat, in order to reduce the variability of the method.
Michael Walker, Senior
Scientist, LGC’s Science & Technology Division commented:
“Consumers are willing to pay a premium for fresh
poultry but how can they be certain that a product has not been
previously frozen or partially frozen and then thawed? LGC’s latest
research has shown that, the HADH method remains valid to
distinguish between fresh and previously frozen or rapidly frozen
chicken and turkey. However, it cannot identify poultry
products that have been superchilled (or partially frozen) using
the new technologies. In order to ensure that the consumer has as
much protection as possible a new cut-off limit has been
adopted for chicken and the procedure used to press juice from the
meat has been refined.”
Laboratory tests based on
release of the enzyme HADH can be used by UK enforcement
authorities and traders to ensure that unscrupulous fraudsters are
not passing off as fresh, turkey or chicken which had been fully
frozen then thawed.
- Ends -
Notes to
editors